Ruling and plotting device



Jan. 12, 1932. c. L. CLARK 1,840,568

RULING AND PLOTTING DEVICE Filed June 1s,' 1930' 2 Sheets-Sheet 1 FIG.1.

INVENTOR BY ATTORNEYS Jan. 12, 1932. c; L. CLARK 1,840,568

RULING AND PLOTTING DEVICE Filed June 18, 1930 2 sheets-sheet 2 INVENTORBY ATTORNEYS (1 a v/Q Patented Jan. 12, 1932 CLIFFORD L. CLARK, OFFAIRFIELD, MAINE RULING AND rnorrme DEVICE Application filed June 18,1980. Serial No. 461,878.

This invention relates to a ruling device preferably of transparentcharacter which is adaptable for the use of navigators, surveyors andothers in plotting points, laying down hearings or courses, drawinglines of position and for obtaining the geographical position, i. e. thelatitude and longitude of the observer without the necessity of usingsupplemental devices such as parallel rulers and dividers or charts ofany description.

One of the objects of thepresent invention resides in the provision of arule device of the above character which will permit a desired bearing,course, etc. to be directly transposed to a simple blank sheet of paperwith the aid of a pencil only. The particular problem which is to behandled can be computed by any of the well known methods using theruling device as an adjunct thereto for plotting the points, drawing thelines, etc.

A further object of the present invention resides in the provision of adevice which is adaptable for the obtaining of various kinds ofnavigational data involving latitude, longitude and direction and inwhich all of the pertinent data is available on the device itself andalso in which rule guiding and plotting means is also provided on thedevice itself so that with the use of the device, in connection with apencil and a sheet of paper only, the desired navigational data can besecured.

It is accordingly a further object of the present invention to provide adevice of this character which will permit the use of charts, parallelrulers and dividers to be dispensed with and in which the desired datacan be obtained more expeditiously than heretofore.

Further and other objects of thepresent invention will be hereinafterpointed out in the accompanying specifications and claims and shown inthe drawings which by way of illustration show what I now consider to bea preferred embodiment of the invention.

In the drawings:

Figure 1 shows my improved rule somewhat enlarged; and

Fig. 2 shows a diagram illustrating one manner of use of the rule forsecuring certain navigational data.

In more detail the rule comprises a sheet 10 of transparent materialsuch as celluloid or the like. The size may be varied in ac' cordancewith the degree of accuracy desired. In practice, however, a convenientsize is about 4" by 7 Preferably the marginal edges of the rule arebevelled so that these edges may be more conveniently used for rulinglines. There is also provided rule guiding and plotting means preferablycomprising a centrally disposed ruling slot designated 11. This slotshould be comparatively narrow to permit the insertion of a fine pencilpoint and also it is desirable that the edges be somewhat bevelled. Thisslot at the top and bottom terminates at the ends of the 30 scale.

The ruling device is suitably engraved, cut or printed upon one face orupon both faces with certain graduations and scales which will behereafter more fully described. If desired, certain scales orgraduations can be placed'on one face and others upon the other or allof the graduations and markings can be placed on one face.

Protractor graduations being provided for each quadrant and a second setrunning from O to 360 being provided for the complete set of protractorgraduations. Thus it will be noted that the two extremities of the lineof the slot 11 will be 0360 and 0180 and a line at right angles to thisgroove and bisecting' it will align with 9090 and 9Q-270.

Longitude scale The longitude scale is comprise of a series ofequidistant parallel straight lines 13 which run both lengthwise andcrosswise on the transparent member, and which divide the entire face ofthe rule into equal squares which may be proportioned to a dimension offor example one-tenth of an inch to a side. This arrangement ofgraduations represents the scale of a Mercator projection or chart,one-tenth of an inch being equivalent to (1') one minute of longitude onthe equator. Since on a Mercator projection the units of longitude aremade to appear everywhere equal, it will be apparent that the longitudescales will remain constant for use in any latitude. Preferably forfacility in reading, every fifth line 13 is displayed relatively moreboldly or by a heavier line. Latitude scales There are also a series ofstraight latitude scales 14 provided on the transparent member which runlengthwise of the rule .as shoWn and which are parallel with each other.These scales cover the entire face of the rule except at the borderportions where the protractor and longitude scales are shown. Thesescales 14 are provided one for each degree of latitude from 0, theequator, to 'north or south or further if desired. Each of the latitudescales is graduated proportionately to the previously mentionedlongitude scales on the Mercator principle.

For a further explanation reference may be had to the American PracticalNavigator by Bowditch, Chapter II, article 43. Hereafter for conveniencein expression, the portion of the rule covered by the latitude scaleswill be termed the graph. The parallels of this graph are so spaced thatthe distance between any adjacent two of them is preferably .05 of aninch or 30 (30 seconds) i. e. onehalf minute of longitude. Accordingly,it will be appreciated that longitude can be measured lengthwise oracross and between any twopoints on the rule.

The scales 14 are individually graduated with a series of small dots ordashes 15 and the space between any adjacent two of these dot or dashgraduations upon any individual scale 14 is equivalent to one minute oflatitude (1) or one nautical mile. Every fifth latitude parallel on thegraph is graduated by dashes to facilitate reading andtheseparticularscales are numbered at their extremities with the .13, it will be notedthat upon the graph portion of the rule that the 1 graduations oflongitude are further sub-divided by inter mediate parallel transverselines 17. These lines 17 in conjunction with the paralles of thelatitude scales divide the face of the graph into equal squares of /2 ofan inch or minute of longitude. All of these parallel lines across thegraph are'thus closely spaced in order that any point on any of thelatitude scales may be more accurately transferred perpendicularly overto the pencil slot so that a point can be plotted therein in an accuratemanner.

In the use of the rule it is intended that the use of charts be whollydispensed with. Furthermore no parallel rulers, dividers or like devicesneed be used. All that is needed is the rule, a sheet of blank paperwhich is placed under the rule and a sharp pencil together with aknowledge of the manner of use of the rule. The rule itself contains onits face all of the requisite longitude data, all of the requisitelatitude data and all of the protractor data which is required forworking out various nagivational and like problems involving latitude,longitude and direction.

Method of asz'ng'rale Various of the sundry plottings, laying down ofbearings and courses and drawing of lines of position can be obtained bythe use of the rule and the rule is also adaptable for use to obtain thesame results in a variety of ways. For the purpose of explaining what isconsidered to be the most convenient method of using the rule there hasbeen selected the example given in Chapter XV, Article 380, H. O. #9(Bowditch) wherein the intersection of two Sumner lines, i. e. the shipsposition, is found by computation, the ships run between observationsbeing involved and the foregoing illustrative ex- III lows 40' S. lAzimuth at right angles 115 3 1' W! to line, N. 51 E.

25 25".S. Azimuth at' right angles 115 33.5-W. to line,'N. 72 W.

and supposing the vessel from which the observations were taken thatgave these lines to have runN. 54 E. (true) miles in the intervalbetween the sights, find the position of the vessel at the time of thesecond sight.

For the purpose of explanation, let the extremity of the line containingthe pencil slot 11 marked 0-360 be -called North, the opposite extremitymarked 0-180 South, the extremity of the central or 0 line of the graphmarked 90 East and its opposite marked 90-270 West.

W'ith the rule, first draw on a blank sheet of paper two lines 1 and 2(see Fig. 2) which intersect each other at right angles. Either the slot11 or the sides of the rule can be used to obtain the 90 relation of thelines. Let line 1 represent parallel of latitude 25 S. and line 2meridian of longitude 115 31 W. The intersection of these linesis thepoint A through which the first Sumner line or line of position is to bedrawn, but since this line must be advanced in a direction N. 54 E.(true) 35 miles, i. e. the ships run between sights, it is unnecessaryto draw the line through point A here.

Now place the center of the protractor, North end toward top of diagramover the point A in such manner that the pencil slot 11 coincides withthe meridian line 2. Plot a point where the 54th graduation of the pro-I guidance of the closely spaced parallel lines cutting all latitudescales perpendicularly. From this intersection. measure off on the 25latitude, scale 35 or miles. This brings us to a point on the North endof the rule'where the 10 curve intersects the scale. Transfer this pointperpendicularly to the pencil slotand call it A. A then is the point 35miles N. 54 E. from the point A through which the first Sumner line N.39 W., at right angles to the azimuth A is to be drawn.

Place center of the rule and the protractor over point A so that theparallel of latitude 25 40 S. coincides with or is parallel to any ofthe East and West lines on the rule. Plot a point where the 39thgraduation of the protractor, West of North, cuts the paper. Call thispoint a'.- Draw straight line through line.

points A and a. A a is the first Sumner Next, to draw second Sumnerline, place rule with North end toward top of diagram, in such mannerthat meridian 115 31 W.

coincides with 35 latitude scale and parallel of latitude 25 40 S. cutsthe 25 latitude scale at its intersection with the 15 curve on South endof rule. Plot point at center of rule, this is point B in latitude 2525' S. longitude 115 33.5 W. through which the second position line isto be drawn running N. 18 E. at right angles to azimuth B.

\Vithout moving rule from its former position, plot point 6 where the18th graduation of the protractor, east of North, cuts the paper. Drawstraight line through points B and b intersecting line A a at C. B?)then is the second Sumner line and C is the ships position at the timeof the second observation.

Now move the rule with North end toward top of diagram to such positionthat point C falls in the 25 latitude scale, parallel 25 40 S. cuts samescale at its intersection with the South 25 curve and is parallel to theEast The foregoing example has shown how the ,7

rule can be utilized for plotting points, laying down courses andbearings and obtaining the shlps position. Other uses will be apparentto those familiar with problems of this character and the particularmanner of computing the data necessary in the solution of such problemsmay be varied as desired.

The data to be employed in using the rule can be obtained in connectionwith the solution of any problem of the position line whether Sumners,Marc St. Hilaires, Weems or any of the methods explained by theHydrographic Ofiice publications be used.

What I claim is:

1. A rule device for plotting points and ruling lines upon sheets ofpaper, said rule comprising a transparent member provided with a pencilreceiving ruling and plotting slot therein, said transparent memberhaving thereon two sets of longitude scales, each set extendingsubstantially completely across the transparent member and therespective sets being at right angles to each other to form a series ofsquare rulings over substantially the entire face of the transparentmember, latitude scales and protractor graduatherein, said transparentmember having raduated over substantially its entiresurace parallellines representative of longi-,

' tude scales, and also having graduated there- 7 on superimposedpa-rallel latitude scales, said member also having graduated thereonprotractor graduations, said transparent member also havin in additioncurved lines to aid in reading t e graduations of the latitude scales,said curved lines diverging from the adjacent curved lines as theyprogress from the zero latitude scale to higher latitude scales.

3. A rulingdevice for plotting points and ruling lines upon sheets 0paper, said ruling device comprising a transparent member provided witha pencil receiving ruling and plotting slot therein, said transparentmember having longitude scales disposed lengthwise and transversethereof with the pencil slot parallel to the scales which extend in onedirection, said member also having latitude scales disposed to intersectand extend above and below a transverse median line which intersects thepencil slot 1 at' right angles and which is representative of 0 minutesof latitude on any of the latitude scales.

In testimony whereof I hereto afiix my signature.

CLIFFORD L. CLARK.

